ICs take a multitude forms, including digital memory chips, microprocessors, application specific integrated circuits (ASICs), application specific standard products (ASSPs), field-programmable gate arrays (FPGAs), hardware security modules (HSMs), and more. There are many systems containing ICs in which it is important to protect the electronically stored and/or processed data, including, but not limited to, computer access control, military weapons systems, medical information, vehicle control, secure communications, and payment transaction processing. The security for the data these systems process often relies on cryptographic operations based on secret keys stored in memory or other circuitry, which are then used to cryptographically secure sensitive data from unauthorized access.
Information leaked from cryptographic circuits via side channels, such as electromagnetic emanations or power consumption variations during the aforementioned cryptographic processes, can be analyzed to determine the secret keys or sensitive data being processed. Masking keys and data can reduce leakage somewhat, but a significant amount of this side channel information leakage may still occur, such as due to transients in the combinatorial logic cloud which are correlated with the data being processed.